• Communications of the Korean Mathematical Society
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• v.28 no.2
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• pp.383-396
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• 2013

We consider an M/PH/1 queue with deterministic impatience time. An exact analytical expression for the stationary distribution of the workload is derived. By modifying the workload process and using Markovian structure of the phase-type distribution for service times, we are able to construct a new Markov process. The stationary distribution of the new Markov process allows us to find the stationary distribution of the workload. By using the stationary distribution of the workload, we obtain performance measures such as the loss probability, the waiting time distribution and the queue size distribution.

• The Korean Journal of Pain
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• v.28 no.4
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• pp.287-289
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• 2015

Brachial plexus block (BPB) under ultrasound guidance has come to be widely used. However, nerve injury has been reported following ultrasound-guided BPB. We hypothesized that BPB under ultrasound guidance in conjunction with real-time electrical nerve stimulation would help us prevent nerve injury and do more successful procedure. Here, we report the successful induction and maintenance of ultrasound-guided BPB and the achievement of good peri- and postoperative pain control using a conductive catheter, the EpiStim$^{(R)}$.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.237-237
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• 2006

P(VDF/TrFE(72/28) ultrathin films were used in the fabrication of Metal-Ferroelectric polymer-Metal (MFM) single bit device with special emphasis on uniform film surface, faster dipole switching time under applied external field and longer memory retention time. AFM and FTIR-GIRAS were complementary in analyzing surface crystalline morphology and the resultant change in chain orientation with varying thermal history. DC-EFM technique was used to 'write-read-erase' the data on the memory bit in a much faster time than P-E studies. The results obtained from this study will enable us to have a good understanding of the ferroelectric and piezoelectric behavior of P(VDF/TrFE)(72/28) thin films suitable for high density data storage applications.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2195-2199
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• 2007

We demonstrate that high-resolution (~60 nm) near-field fluorescence images of fluorescent nanospheres can be obtained by utilizing the tip-induced fluorescence quenching process. A time-stamped photon counting (TSPC) technique employed enables us to efficiently measure the degree of fluorescence quenching caused by the dielectric or metallic atomic force microscopy tip. We find that the degree of quenching is not only determined by the tip-material but also by the local morphology of the tip. The fringe patterns around individual nanospheres observed are explained in terms of the interference between the excitation field that is directly induced by the laser source, and the scattered excitation field from the tip.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2253-2260
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• 2007

A series of tetra donor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were synthesized in neutral and cationic forms. The imaging activity of overall set of fluorophores was studied by the two-photon induced fluorescence (TPIF) method in a range of solvents. We also measured a clear progression toward a longer photoluminescence lifetime with increasing solvent polarity (intrinsic photoluminescence lifetime, τi: ~2 ns in toluene → 12-16 ns in water). The paracyclophane fluorophores with this unique property can be utilized as an optical polarity probe for the biomolecular substrates. The combined measurement of the two-photon fluorescence microscopy (TPM) cell image and TPIF lifetime can give us a better understanding of the biological processes and local environments in the cells.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.259-262
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• 2005

This paper deals with the shear strengthening effect of RC beams strengthened with carbon fiber sheets. Fifteen strengthened RC beams(including control beam) were experimentally evaluated to determine improvements in shear strength. The major parmeters of experiment variables are fiber sheet strengthening ratios and strengthening methods of fiber sheet(I-S, I-W, U-S, U-W type). Reinforced concrete beams strengthened with carbon fiber sheets were tested under the combined control of load. Considering strengthening ratios and strengthening methods of fiber sheet, shear capacity and failure mode of test specimens were evaluated. The results show that shear capacity of beams strengthened with fiber sheet is about $28.82\%$ in IS type, $20.49\%$ in IW type, $26.04\%$ in US type, $28.70\%$ in UW type higher than the strength of control beam.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.127-136
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• 2016

The purpose of this research is to conduct a comparative study on the characteristics of daily volatility spillovers across the stock markets of Korea, China, and Japan. We employ generalized spillover definition and measurement developed by Diebold & Yilmaz (2009, 2012). The sample period is January 5, 1993 to September 25, 2015. From a static full-sample analysis, we find that 8.60% of forecast error variance comes from volatility spillovers. From a 250-day rolling-sample analysis, we discover that there exist significant volatility fluctuations in the stock markets of Korea, China and Japan, expecially during the Asian Financial Crisis (1998-1999) and the US Credit Crisis (2008-2009) after the collapse of Lehman Brothers. From the net directional spillovers across three countries, we come upon that there is neither a definite leader nor a significant follower during the sample period.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.5
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• pp.250-257
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• 2015

As recognized by all scientific and industrial groups, carbon dioxide ($CO_2$) capture and sequestration (CCS) could play an important role in reducing greenhouse gas emissions. This paper is aimed at identifying evolving technological trends from the objective information of patents related to carbon capture technology by solvent. In this study the patents applied in korea, japan, china, canada, US, EU from 1993 to 2013 were analyzed. The result of patent analysis could be used for R&D and policy making of domestic CCS industry.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.28.2-28.2
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• 2010

We investigate star clusters in the Stephan's Quintet using Wide Field Camera 3 of the Hubble Space Telescope and three filters (F438W, F606W, F814W). Stephan's Quintet located at ~ 85 Mpc, so most star clusters are seen like point source even in HST image. We perform the Point Spread Funtion fitting photometry to find star clusters. Then we have selected 749 star cluster candidates by visual inspection. Usinng simple steallr population models (Bruzual & Charlot, 2003), we estimate ages of these star clusters. Many young star clusters found in tidal features of NGC 7318 and NGC 7319. Also star clusters in the shocked region of NGC7318 have younger age than those in NGC 7319 tidal tail. These result implies interaction which distrupt NGC 7319 first, and collision between NGC 7318 A/B occurred. In contrast, old star clusters are mainly located in NGC 7317 and in the center of other galaxies. Implications of these result will be discussed.

• Herbal Formula Science
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• v.28 no.1
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• pp.117-135
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• 2020

Objectives : Xiaochaihutang(小柴胡湯) is a famous herbal prescription in the Traditional Korean Medicine, and its components include Bupleuri Radix(柴胡), Scutellariae Radix(黃芩), Ginseng Radix(人蔘), Pinelliae Tuber(半夏), Glycyrrhizae Radix et Rhizoma(甘草), Zingiberis Rhizoma Crudus(生薑), Zizyphi Fructus(大棗). Methods : In this study, we reviewed the effects of xiaochaihutang by searching Pubmed. And we connected with Korean Standard Classification of Diseases (KCD) and the effects of xiaochaihutang. Results and Conclusion : The effects of xiaochaihutang was related with B18, C22, C34, C56, J30, J45, K70, K74, K76, F32, F33, F34, F41 as indicated by KCD. In clinics, the medical doctors almost use the KCD code for insurance. This review give us the scientific clue of Xiaochaihutang's effect in KCS system.